CXA3010 データシートの表示（PDF） - Sony Semiconductor

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CXA3010

Read/Write Amplifier (with Built-in Filters) for FDDs

Sony Semiconductor 

CXA3010Q

Comparator

The comparator detects the crosspoint of the filter differential output.

Time domain filter

The time domain filter converts the comparator output to read data.

This filter is equipped with two monostable multivibrators. 1st monostable multivibrator eliminates

unnecessary pulses, and 2nd monostable multivibrator determines the pulse width of the read data.

The 1st monostable multivibrator pulse width T1 is determined by the resistor RA between Pin 12 and

A.GND. T1 can be switched as follows by the settings of Pins 9 and 18:

When XHD = High and X360 = High T1(1M) = 88RA + 124 [ns] RA [kΩ]

When XHD = High and X360 = Low or

XHD = Low and X360 = X T1(1.6M/2M) = 44RA + 62 [ns]

The pulse width for 2nd monostable multivibrator is fixed at 400ns.

(2) Write system

Write data input through Pin 2 is frequency-divided by the T flip-flop and generates the recording current for

the head. The recording current can be switched by the settings of Pins 9 and 18.

The write current IW is set by the resistors RW connected between Pin 25 and VCC, between Pin 26 and VCC,

and between Pin 27 and VCC.

IW = 3.53/RW [mAO-P] RW [kΩ]

Furthermore, the inner/outer track write current IW can be changed for each mode by switching Pin 4.

However, the current ratio between the inner and outer tracks is fixed.

(3) Erase current

The erase current IE is set by the resistor RE between Pin 28 and VCC.

IE = 11.8/RE [mA] RE [kΩ]

Pins 30 and 31 are constant current outputs.

In addition, in order to minimize the R/W head crosstalk time constants are provided for the rise and fall of

the erase current. For details, refer to page 20 and page 21.

(4) Power on/off detection system

The power on/off detection system detects a reduced voltage in the supply voltage.

When VCC is below the specified value, the write system and erase system cease operation, disabling the

write and erase functions.

Notes on Operation

• Select the voltage gain so that the preamplifier output amplitude is 1Vp-p or less.

If the preamplifier output amplitude exceeds 1Vp-p, the filter output waveform becomes distorted.

• Observe the following point when mounting this device.

• The ground should be as large as possible.

– 16 –

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